There are only five medications currently FDA-approved for the treatment of Alzheimer's Disease (AD). Four are cholinesterase inhibitors: tacrine (COGNEX®; Sciele), donepezil (ARICEPT®; Pfizer), rivastigmine (EXELON®; Novartis), and galantamine (RAZADYNE®; Ortho-McNeil-Janssen). Donepezil, rivastigmine, and galantamine are successors to tacrine, a first generation compound rarely prescribed because of the potential for hepatotoxicity; they are roughly equally efficacious at providing symptomatic improvement of cognition and function at all stages of AD. The fifth approved medication is memantine (NAMENDA®; Forest), a low-affinity, use dependent N-methyl-D-aspartate glutamate receptor antagonist that offers similar benefits, but only in moderate to severe AD. The clinical effects of these compounds are small and impermanent, and currently available data are inconclusive to support their use as disease modifying agents. See, e.g., Kerchner et al, 2010, Bapineuzumab, Expert Opin Biol Ther., 10(7):1121-1130. Clearly, alternative approaches to treatment of AD are required.
Certain isoindoline compounds are provided that act as sigma-2 receptor functional antagonists and inhibit the deleterious effects of soluble Aβ oligomers. In some embodiments, isoindoline sigma-2 receptor antagonist compounds and compositions are used to treat or prevent synaptic dysfunction in a subject.